1\documentclass[a4paper]{article} 2\usepackage{standalone} 3\usepackage{newclude} 4\usepackage[a4paper,margin=2cm]{geometry} 5\usepackage{multicol} 6\usepackage{multirow} 7\usepackage{amsmath} 8\usepackage{amssymb} 9\usepackage{harpoon} 10\usepackage{tabularx} 11\usepackage{makecell} 12\usepackage[dvipsnames, table]{xcolor} 13\usepackage{blindtext} 14\usepackage{graphicx} 15\usepackage{wrapfig} 16\usepackage{tikz} 17\usepackage{tikz-3dplot} 18\usepackage{pgfplots} 19\pgfplotsset{compat=1.8} 20\usepackage{mathtools} 21\usetikzlibrary{calc} 22\usetikzlibrary{angles} 23\usetikzlibrary{datavisualization.formats.functions} 24\usetikzlibrary{decorations.markings} 25\usepgflibrary{arrows.meta} 26\usepackage{longtable} 27\usepackage{fancyhdr} 28\pagestyle{fancy} 29\fancyhead[LO,LE]{Year 12 Methods} 30\fancyhead[CO,CE]{Andrew Lorimer} 31\providecommand{\tightlist}{\setlength{\itemsep}{0pt}\setlength{\parskip}{0pt}} 32\setlength{\parindent}{0cm} 33\usepackage{mathtools} 34\usepackage{xcolor}% used only to show the phantomed stuff 35\setlength\fboxsep{0pt}\setlength\fboxrule{.2pt}% for the \fboxes 36\newcommand*\leftlap[3][\,]{#1\hphantom{#2}\mathllap{#3}} 37\newcommand*\rightlap[2]{\mathrlap{#2}\hphantom{#1}} 38\newcolumntype{L}[1]{>{\hsize=#1\hsize\raggedright\arraybackslash}X} 39\newcolumntype{R}[1]{>{\hsize=#1\hsize\raggedleft\arraybackslash}X} 40\definecolor{cas}{HTML}{e6f0fe} 41\definecolor{shade1}{HTML}{ffffff} 42\definecolor{shade2}{HTML}{e6f2ff} 43\definecolor{shade3}{HTML}{cce2ff} 44\linespread{1.5} 45\newcommand{\midarrow}{\tikz \draw[-triangle 90] (0,0) -- +(.1,0);} 46\newcommand{\tg}{\mathop{\mathrm{tg}}} 47\newcommand{\cotg}{\mathop{\mathrm{cotg}}} 48\newcommand{\arctg}{\mathop{\mathrm{arctg}}} 49\newcommand{\arccotg}{\mathop{\mathrm{arccotg}}} 50\pgfplotsset{every axis/.append style={ 51 axis x line=middle, % centre axes 52 axis y line=middle, 53 axis line style={->}, % arrows on axes 54 xlabel={$x$}, % axes labels 55 ylabel={$y$}, 56}} 57\begin{document} 58 59\title{\vspace{-2cm}\hrule\vspace{0.4cm} Year 12 Methods} 60\author{Andrew Lorimer} 61\date{} 62\maketitle 63 64\begin{multicols}{2} 65 66\section{Functions} 67 68\begin{itemize} 69\tightlist 70\item vertical line test 71\item each \(x\) value produces only one \(y\) value 72\end{itemize} 73 74\subsection*{One to one functions} 75 76\begin{itemize} 77\tightlist 78\item 79 \(f(x)\) is \emph{one to one} if \(f(a) \ne f(b)\) if 80 \(a, b \in \operatorname{dom}(f)\) and \(a \ne b\)\\ 81 \(\implies\) unique \(y\) for each \(x\) (\(\sin x\) is not 1:1, 82 \(x^3\) is) 83\item 84 horizontal line test 85\item 86 if not one to one, it is many to one 87\end{itemize} 88 89\subsection*{Finding inverse functions \(f^{-1}\)} 90 91\begin{itemize} 92\tightlist 93\item 94 if \(f(g(x)) = x\), then \(g\) is the inverse of \(f\) 95\item 96 reflection across \(y-x\) 97\item 98 \(\operatorname{ran} \> f = \operatorname{dom} \> f^{-1}, \quad \operatorname{dom} \> f = \operatorname{ran} \> f^{-1}\) 99\item 100 inverse \(\ne\) inverse \emph{function} (i.e.~inverse must pass 101 vertical line test)\\ 102 \(\implies f^{-1}(x)\) exists \(\iff f(x)\) is one to one 103\item 104 \(f^{-1}(x)=f(x)\) intersections may lie on line \(y=x\) 105\end{itemize} 106 107\subsubsection*{Requirements for showing working for \(f^{-1}\)} 108 109\begin{enumerate} 110\def\labelenumi{\arabic{enumi}.} 111\tightlist 112\item 113 start with \emph{``let \(y=f(x)\)''} 114\item 115 must state \emph{``take inverse''} for line where \(y\) and \(x\) are 116 swapped 117\item 118 do all working in terms of \(y=\dots\) 119\item 120 for sqrt, state \(\pm\) solutions then show restricted 121\item 122 for inverse \emph{function}, state in function notation 123\end{enumerate} 124\subsubsection*{Solving 125\(\protect\begin{cases}px + qy = a \\ rx + sy = b\protect\end{cases} \>\) 126for \(\{0,1,\infty\}\) 127solutions} 128 129where all coefficients are known except for one, and \(a, b\) are known 130 131\begin{enumerate} 132\tightlist 133\item 134 Write as matrices: 135 \(\begin{bmatrix}p & q \\ r & s \end{bmatrix}\begin{bmatrix} x \\ y \end{bmatrix} = \begin{bmatrix} a \\ b \end{bmatrix}\) 136\item 137 Find determinant of first matrix: \(\Delta = ps-qr\) 138\item 139 Let \(\Delta = 0\) for number of solutions \(\ne1\)\\ 140 or let \(\Delta \ne0\) for one unique solution. 141\item 142 Solve determinant equation to find variable \\ 143\textbf{For infinite/no solutions:} 144\item 145 Substitute variable into both original equations 146\item 147 Rearrange equations so that LHS of each is the same 148\item 149 \(\text{RHS}(1) = \text{RHS}(2) \implies (1)=(2) \> \forall x\) 150 (\(\infty\) solns)\\ 151 \(\text{RHS}(1) \ne \text{RHS}(2) \implies (1)\ne(2) \> \forall x\) (0 152 solns) 153\end{enumerate} 154 155\colorbox{cas}{On CAS:} Matrix \(\rightarrow\) \texttt{det} 156 157\subsubsection*{Solving \(\protect\begin{cases}a_1 x + b_1 y + c_1 z = d_1 \\ a_2 x + b_2 y + c_2 z = d_2 \\ a_3 x + b_3 y + c_3 z = d_3\protect\end{cases}\)} 158 159\begin{itemize} 160\tightlist 161\item 162 Use elimination 163\item 164 Generate two new equations with only two variables 165\item 166 Rearrange \& solve 167\item 168 Substitute one variable into another equation to find another variable 169\end{itemize} 170\subsection*{Odd and even functions} 171 172Even when \(f(x) = -f(x)\)\\ 173Odd when \(-f(x) = f(-x)\) 174 175Function is even if it is symmetrical across \(y\)-axis 176\hspace{5em}\(\implies f(x)=f(-x)\)\\ 177Function \(x^{\pm{p \over q}}\) is odd if \(q\) is odd\\ 178 179\begin{tabularx}{\columnwidth}{XX} 180\textbf{Even:} & \textbf{Odd:} \\ 181\begin{tikzpicture}\begin{axis}[ticks=none, yticklabels={,,}, xticklabels={,,}, xmin=-3, xmax=3, scale=0.4, samples=100, smooth, unbounded coords=jump]\addplot[blue, mark=none] {(x^2)}; \end{axis}\end{tikzpicture} & 182\begin{tikzpicture}\begin{axis}[ticks=none, yticklabels={,,}, xticklabels={,,}, xmin=-3, xmax=3, scale=0.4, samples=100, smooth, unbounded coords=jump]\addplot[blue, mark=none] {(x^3)}; \end{axis}\end{tikzpicture} 183\end{tabularx} 184\pagebreak 185\pgfplotsset{every axis/.append style={ 186 xlabel=, % put the x axis in the middle 187 ylabel=, % put the y axis in the middle 188}} 189\begin{table*}[ht] 190\centering 191\begin{tabularx}{\textwidth}{r|X|X} 192 & \(n\) is even & \(n\) is odd \\ \hline 193 \(x^n, n \in \mathbb{Z}^+\) & 194\makecell{\\\begin{tikzpicture}\begin{axis}[yticklabels={,,}, xticklabels={,,}, xmin=-3, xmax=3, scale=0.4, samples=100, smooth, unbounded coords=jump]\addplot[orange, mark=none] {(x^2)}; \end{axis}\end{tikzpicture}} & 195\makecell{\\\begin{tikzpicture}\begin{axis}[yticklabels={,,}, xticklabels={,,}, xmin=-3, xmax=3, scale=0.4, samples=100, smooth, unbounded coords=jump]\addplot[orange, mark=none] {(x^3)}; \end{axis}\end{tikzpicture}} \\ 196 \(x^n, n \in \mathbb{Z}^-\) & 197\makecell{\\\begin{tikzpicture}\begin{axis}[yticklabels={,,}, xticklabels={,,}, xmin=-4, xmax=4, ymax=8, ymin=-0, scale=0.4, smooth]\addplot[orange, mark=none, samples=100] {(x^(-2))}; \end{axis}\end{tikzpicture}} & 198\makecell{\\\begin{tikzpicture}\begin{axis}[yticklabels={,,}, xticklabels={,,}, xmin=-3, xmax=3, scale=0.4, samples=100, smooth]\addplot[orange, mark=none] {(x^(-1))}; \end{axis}\end{tikzpicture}} \\ 199 \(x^{\frac{1}{n}}, n \in \mathbb{Z}^-\) & 200\makecell{\\\begin{tikzpicture}\begin{axis}[yticklabels={,,}, xticklabels={,,}, xmin=-1, xmax=5, scale=0.4, samples=100, smooth, unbounded coords=jump]\addplot[orange, mark=none] {(x^(1/2))}; \end{axis}\end{tikzpicture}} & 201\makecell{\\\begin{tikzpicture} 202\begin{axis}[enlargelimits=false, yticklabels={,,}, xticklabels={,,}, xmin=-3, xmax=3, ymin=-3, ymax=3, smooth, scale=0.4] 203\addplot[orange,domain=-2:2,samples=1000,no markers] gnuplot[id=poly]{sgn(x)*(abs(x)**(1./3)) }; 204\end{axis} 205\end{tikzpicture}} 206\end{tabularx} 207\end{table*} 208\pgfplotsset{every axis/.append style={ 209 xlabel=\(x\), % put the x axis in the middle 210 ylabel=\(y\), % put the y axis in the middle 211}} 212 213\section{Polynomials} 214 215\subsection*{Quadratics} 216 217\[ x^2 + bx + c = (x+m)(x+n) \] 218\hfill where \(mn=c, \> m+n=b\) 219 220\begin{align*} 221\hline 222\textbf{Difference} && a^2 - b^2 &= (a-b)(a+b) \\[2ex] 223\textbf{Perfect sq.} && a^2\pm2ab + b^2 &= (a \pm b^2) \\[2ex] 224\textbf{Completing} && x^2+bx+c &= (x+\frac{b}{2})^2+c-\frac{b^2}{4} \\ 225 && ax^2+bx+c &= a(x-\frac{b}{2a})^2+c-\frac{b^2}{4a} \\[2ex] 226\textbf{Quadratic} && x &= \dfrac{-b\pm\sqrt{b^2-4ac}}{2a} \\ 227 && & \text{where}\Delta=b^2-4ac \\ 228\hline 229\end{align*} 230 231\subsection*{Cubics} 232 233\textbf{Difference of cubes:} \(a^3 - b^3 = (a-b)(a^2 + ab + b^2)\)\\ 234\textbf{Sum of cubes:} \(a^3 + b^3 = (a+b)(a^2 - ab + b^2)\)\\ 235\textbf{Perfect cubes:} \(a^3\pm3a^2b + 3ab^2\pm b^3 = (a \pm b)^3\) 236 237\[ y=a(bx-h)^3 + c \] 238 239\begin{itemize} 240\tightlist 241\item 242 \(m=0\) at \emph{stationary point of inflection} 243 (i.e.~(\({h \over b}, k)\)) 244\item 245 in form \(y=(x-a)^2(x-b)\), local max at \(x=a\), local min at \(x=b\) 246\item 247 in form \(y=a(x-b)(x-c)(x-d)\): \(x\)-intercepts at \(b, c, d\) 248\item 249 in form \(y=a(x-b)^2(x-c)\), touches \(x\)-axis at \(b\), intercept at 250 \(c\) 251\end{itemize} 252 253\subsection*{Linear and quadratic 254graphs} 255 256\subsubsection*{Forms of linear 257equations} 258 259\begin{itemize} 260\tightlist 261\item \(y=mx+c\) 262\item \(\frac{x}{a} + \frac{y}{b}=1\) where \((x_1, y_1)\) lies on the graph 263\item \(y-y_1 = m(x-x_1)\) where \((a,0)\) and \((0,b)\) are \(x\)- and \(y\)-intercepts 264\end{itemize} 265 266\subsection*{Line properties} 267 268Parallel lines: \(m_1 = m_2\)\\ 269Perpendicular lines: \(m_1 \times m_2 = -1\)\\ 270Distance: \(|\vec{AB}| = \sqrt{(x_2 - x_1)^2 + (y_2 - y_1)^2}\) 271 272\subsection*{Quartic graphs} 273 274\subsubsection*{Forms of quartic 275equations} 276 277\(y=ax^4\)\\ 278\(y=a(x-b)(x-c)(x-d)(x-e)\)\\ 279\(y=ax^4+cd^2 (c \ge0)\)\\ 280\(y=ax^2(x-b)(x-c)\)\\ 281\(y=a(x-b)^2(x-c)^2\)\\ 282\(y=a(x-b)(x-c)^3\) 283 284\subsection*{Simultaneous equations 285(linear)} 286 287\begin{itemize} 288\tightlist 289\item 290\textbf{Unique solution} - lines intersect at point 291\item 292\textbf{Infinitely many solutions} - lines are equal 293\item 294\textbf{No solution} - lines are parallel 295\end{itemize} 296 297 298\input{temp/transformations} 299\input{temp/stuff} 300\input{circ-functions} 301\input{temp/calculus} 302 303\end{multicols} 304\end{document}